The support building of the Wardenclyffe tower had a boiler room, with its own railway coal supply.
I have pictures of the boiler room, but I can't find them so quickly.
(here is some more info on that)
These boilers provided steam for the 250 KW generator that in turn provided electricity for the tower.
I see no reason to assume they served any other purpose.
RE: Verifying Tesla’s theory - first experiments